1. Field of the Invention
The present invention relates to an optical path change member provided at a terminal of a light transmission medium such as an optical fiber, and a holding member body used for the optical path change member. The optical path change member is an optical part for, changing an optical path direction between an optical fiber and a light input and output end provided on a board to optically connect the optical fiber with the light input and output end.
Priority is claimed on Japanese Patent Application No. 2009-210376 filed on. Sep. 11, 2009, the disclosure of which is incorporated herein by reference.
2. Description of the Related Art
In recent years, a scheme of fixing an optical connector assembled with a front end portion of an optical fiber arranged along aboard, on the board to be optically connected to an optical device mounted on the board, such as a light-emitting device such as a vertical cavity surface emitting laser (hereinafter, referred to as a VCSEL) or a light-receiving device such as a photodiode (PD), from or to which light is output or input vertically to the board, has been widely used.
A structure for changing an optical path to optically connect the optical fiber with the optical device is provided in such an optical connector. As a representative optical connector having this structure, a photonic turn, optical connector (a PT optical connector) for changing an optical axis by 90° inside the connector (standardized in JPCA-PE03-01-06S) is available.
The PT optical connector is a board-mounted optical connector for optically connecting a multi-core optical fiber, such as a multi-core optical fiber ribbon, with an optical device on a flexible wiring board. The PT optical connector has begun to be used for optical interconnection of a router, a server, a parallel computer and the like.
An optical path change member for changing an optical path direction of a multi-core optical fiber is disclosed in Japanese Unexamined Patent Application, First Publication No. 2006-184782. The optical path change member changes an optical path of two-dimensionally arranged multi-core optical fibers. In the optical path change member, the multi-core optical fibers in an upper row are inclined with respect to the multi-core optical fibers in a lower row, and front ends of the optical fibers in the upper and lower rows are closer. This prevents a great optical path difference. The optical path change member is of an outer-surface reflection type in which light output from the optical fiber or an optical device collides with a reflective surface from the outside of an optical path change member body.
An optical module is used as the optical device connected with the multi-core optical fiber. This optical module is an optical part including a multi-channel light-emitting device, a multi-channel light-receiving device, and a transmitting and receiving circuit.
An inner-surface reflection type of a PT optical connector in which light from the inside of an optical path change member body collides with a reflective surface through the inside of the optical path change member body is disclosed as an optical path change member in Japanese Unexamined Patent Application, First Publication No 2007-121973. A lens is formed on a lower surface of the optical path change member. Light output from a front end of an optical fiber is totally reflected toward a circuit board by the reflective surface, focused by the lens, and optically connected with a light input and output end of the circuit board. When the optical device of the circuit board is a light-emitting device, light output from the light-emitting device is focused by the lens, totally reflected by the reflective surface, and optically connected with the front end of the optical fiber.
A PT optical connector in which multi-core optical fibers are two-dimensionally arranged is disclosed in Japanese Unexamined Patent Application, First Publication No. 2006-184680. In the optical path change member, the optical fiber hole arrays corresponding to the multi-core optical fibers are shifted from each other. As the optical fiber hole arrays are arranged to be shifted from each other, light interference can be prevented.
However, the reflective surface in the conventional optical path change member is an inclined flat surface. Accordingly, it is difficult to change an optical path of incident light in an optimal direction. If the reflective surface is the flat inclined surface, optical connection may not be maintained when the direction of the incident light is shifted. In particular, if the multi-core optical fibers are two-dimensionally arranged, it is difficult to position the multi-core optical fiber and the optical device with respect to each other.
The present invention has been achieved in view of the above circumstances, and it is an object of the present invention to provide an optical path change member for allowing an optical path to be accurately changed on a reflective surface even when multi-core optical fibers are two-dimensionally arranged, and a holding member body used for the optical path change member.